Improvement in relief-valves for fire-engines



A-. F. ALLEN.

Re lief-Valve for Fire-Engines N0, 127L609, Patented May 21,1 872.

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ALBERT F. ALLEN, OF PROVIDENCE, RHODE ISLAND.

IMPROVEMENT IN RELIEF-VALVES FOR FIRE-ENGINES.-

Specification forming part of Letters Patent No. 127,009, dated May 21, 1872.

To all whom it may concern:

Be it known that I, ALBERT F. ALLEN, of the city and county of .Providence, in the State of Rhode Island, have invented a certain new and useful Improvement in Reliefgalves for Fire-Engines, Pumps, Hydrants,

My improvement relates particularly to such peculiar relief-valves as were invented by me and described in my Letters Patent dated April 18, 1871, and subsequently improved, as set forth in other Letters Patent dated November 14, 1871. My present invention consists in combining a main reliefvalve, which is held to its closed position by a current of water acting upon a hydraulic lever, with an auxiliary relief-valve, which is kept closed in a manner and by means common to safety-valves, so that the main reliefvalve will never be opened by pressure while the current is flowing, but will be opened by any pressure, however light, when the current ceases to flow; and the auxiliary valve, independent of the current,- will be opened by the water pressure when it exceeds certain desirable and fixed limits, even though there be a continuous current or flowage of water, by means of which the improved valve will be enabled to att'ord complete relief against undue water-pressure, whether resulting from increased force at the pump or from the checking or retention of the water on its way to delivery. My invention further consists in several minor points involved in the construction "and arrangement of the several parts, which are hereafter more fully described; and I do hereby declare that the following specification, taken in connection with the drawing furnished, and forming a part of the same, is a true, clear, and exact description of a reliefvalve embodying the several features of my invention.

Referring to the drawing, Figure 1 represents one of my improved relief-valves in perspective. Fig. 2 represents the same in longitudinal vertical section, with the main and auxiliary relief-valves closed. Fig. 3 represents the same, with the main valve closed and the auxiliary relief-valve open.

A denotes the main chamber of the valve. It is connected, when in practical use, at a with a pipe leading to the interior of the base of the air-chamber of a forcing-pump, with which it is to be used. All water flowing from pump to hose passes through this chamber in the direction of the arrow No. 1. B denotes an auxiliary valve-chamber. It communicates with the interior of the main (51131111 her A, and also, by a proper pipeconnection, with the suction-chamber of the pump through the port K. 0 denotes the main relief-valve, which controls the opening directly connecting the main with the auxiliary chamber. In this instance the valve and its stem 1) are cast in one piece. This stem is fitted to hearings in the neck 0, which is in turn fitted, by a screw-connection, to the shell of the auxiliary chamber. Between the stem and the neck 0 a water-packin g is effected by a sufficient number of annular grooves, out either in the stem or in the neck, as may be deemed preferable. E denotes the hydraulic lever, pivoted to bearings in the upper portion of the main valve chamber. Its long end is curved longitudinally, and is fitted so as to be acted upon by the current of water, when forced through the chamber, with as much power as possible. Its short end is attached to the lower end of the valve-stem by means of a hollow screw-link, d, provided with a slotted neck,which receives the end of the hydraulic lever. the valve-stem the screw-link 61 will be projected from or withdrawn into it, and thus afford a means of adjusting the relative positions of the lever and valve. As-so far described the relief-valve does not differ materially from the improved valve patented by me November 14, 1871. It will be observed that the valve'stem D is tubular in its structure, and that its interior communicates with the interior'of the main chamber through the openings 6 in the screw-link d. E denotes the auxiliary relief-valve. It is in this instance a solid cylindrical plunger, fitted to the interior of the valve-stem D. It is also provided with annular recesses, by which a water-packing is effected. The auxiliary valve-chamber B and the main valve-chamber communicate not only through the opening guarded by the main relief-valve C, but also through the interior of i the stem, by the way of ports f in the valvestem and ports 6. in the screw-link d. The auxiliary valve F guards the ports f when its lower end extends below them, and the flange,

By turning at its upper end, rests on an annular shelf within the valve-stem. G denotes a spring for holding the auxiliary relief-valve to its lowest position while guarding the ports f. In this instance two springs, one within the other, are employed. The lower ends of both bear upon the top of the auxiliary valve F. H denotes a screw-cap fitted to the interior of the upper end of the tubular valve-stem D. The upper interior end of the cap is fitted to receive, as a bearing-surface, the upper end of the smaller sprin The lower interior end of the cap is employed as abearing-surface for the upper end of the larger sprin When the shoulder of the auxiliary valve is on the annular shelf in the valve-stem the force of the spring may be adjusted by the screw-cap, and the valve so set that it will resist pressure under certain limits, but open when the limit is reached, after the usual manner of safetyvalves. An indicator or graduated scale may be readily attached, by which the force exercised by the spring may be approximately determined; or by turning down the screw-cap until the springs are set the auxiliary reliefvalve may be closed against any pressure which it would be practicable to bring upon it.

The operation of the improved relief-valve is as follows: Assuming that when in position, as illustrated in Fig. 2, the water is flowing through the main chamber to the hose, and that the main relief-valve is held to its seat by the force of the flowing water acting on the hydraulic lever, it will be readily understood that when the current ceases the main valve will open and allow relief by the passage of water through its opening into the auxiliary chamber B, thence to the pump by the port K, and that the resumption of the current will close the valve. As heretofore constructed no relief could be afforded by the valve, except such as would result from a cessation of the current, and therefore no limit could be set to the degree of pressure from which relief might be desirable, as the relief-valve would open as quick at say ten pounds waterpressure as it would at fifty pounds, provided only that the current of water be checked or stoppedin both cases. In order that the water-pressure may be limited, so as to have it at all times within the resisting capacity of the hose in service, the auxiliary valve is employed. When this valve has been set at, say, fifty pounds, by adjusting the springs with the screw-cap the hydraulic lever will hold the main relief-valve to its seat throughout any pressure under or above fifty pounds so long as the current continues to flow, while the auxiliary relief-valve, on receiving more pressure than that which it is adjusted to resist, will rise and uncover the ports f and allow rclief through the valve-stem, as indicated by the small arrows in Fig. 3.

Having thus described my invention, I claim as new, and desire to secure by Letters Patent 1. The improved automatic relief-valve, consisting of the combination of a main valve, which is kept closed by a current of water acting upon a hydraulic lever, and an auxiliary valve, which is held to its closed position in a manner and by means common tosafetyvalves, in order that undue pressure within the main valve-chamber may be promptly rclieved, whether it result from the increasing force of the pump or the checking or cessation of the current of water flowing from the pump to hose, substantially as described.

2. The combination, within suitable communicatin g chambers, of thehydraulie lever, main relief-valve, tubular valve-stem, and auxiliary relief-valve, substantially as and for the purposes specified.

3. The combination of the main valve and the auxiliary adjustable valve, each being arranged independently of the other, so that either may be opened or closed without affecting or operating the other, substantially as described.

ALBERT F. ALLEN.

Witnesses:

CHARLES SELDEN, HENRY MARTIN. 

